Not-A, representation symmetry-protected topological, and Potts phases in an S-3-invariant chain

Article

关键词: BOND GROUND-STATES;    OPERATOR CONTENT;    CONFORMAL-INVARIANCE;    BOUNDARY-CONDITIONS;    CRITICAL-BEHAVIOR;    MODEL;    SPIN;    MATRIX;    FERROMAGNET;    CHARGE;   

DOI  :  10.1103/PhysRevB.101.235108

来源: SCIE

【 摘 要 】

We analyze in depth an S-3-invariant nearest-neighbor quantum chain in the region of a U(1)-invariant self-dual multicritical point. We find four distinct proximate gapped phases. One has three-state Potts order, corresponding to topological order in a parafermionic formulation. Another has representation symmetry-protected topological (RSPT) order, while its dual exhibits an unusual not-A order, where the spins prefer to align in two of the three directions. Within each of the four phases, we find a frustration-free point with exact ground state(s). The exact ground states in the not-A phase are product states, each an equal-amplitude sum over all states where one of the three spin states on each site is absent. Their dual, the RSPT ground state, is a matrix product state similar to that of Affleck-Kennedy-Lieb-Tasaki. A field-theory analysis shows that all transition lines are in the universality class of the critical three-state Potts model. They provide a lattice realization of a flow from a free-boson field theory to the Potts conformal field theory.

【 授权许可】

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